MC-36456: union implementation

Author: cpartica

dev/tests/api-functional/_files/Magento/TestModuleGraphQlQuery/Model/Resolver/UnionTypeResolver.php

@@ -24,5 +24,4 @@ public function resolveType(array $data): string
         }
         return '';
     }
-
 }

dev/tests/api-functional/testsuite/Magento/GraphQl/TestModule/GraphQlQueryTest.php

@@ -10,7 +10,7 @@
 use Magento\TestFramework\TestCase\GraphQlAbstract;
 
 /**
- * Class GraphQlQueryTest
+ * Test for basic GraphQl features
  */
 class GraphQlQueryTest extends GraphQlAbstract
 {
@@ -25,15 +25,6 @@ public function testQueryTestModuleReturnsResults()
         item_id
         name
     }
-    testUnion {
-      __typename
-      ... on TypeCustom1 {
-          custom_name1
-      }
-      ... on TypeCustom2 {
-          custom_name2
-      }
-    }
 }
 QUERY;